I have given several instances of friendship existing between horses and
dogs.
A fine hunter had formed a friendship with a handsome greyhound which
slept in the stable with him, and generally accompanied him when taken
out for exercise. When the greyhound accompanied his master in his
walks, the horse would look over his shoulder, and neigh in a manner
which plainly said, Let me go also; and when the dog returned, he was
received with an unmistakable neigh of welcome. He would lick the
horse's nose, and in return the horse would scratch his back with his
teeth.
On one occasion the groom had, as usual, taken out the horse for
exercise, followed by the greyhound, when a savage dog attacked the
latter and bore him to the ground. The horse, seeing this, threw back
his ears, and, breaking from the groom, rushed at the strange dog which
was attacking his friend, seized him by the back with his teeth,
speedily making him quit his hold, and shook him till a piece of his
skin gave way. The offender, getting on his feet, scampered off, glad
to escape from a foe who could punish him so severely.